package com.kfm.test;

public class Demo {

    private static int a = 0;

    public static void main(String[] args) {
        modify(a);
        System.out.println(a); // 0

        modify();
        System.out.println(a); // 1

        Student student = new Student();
        student.age = 10;

        modify(student);
        System.out.println(student.age); // 11
    }

    public static void modify(){
        a ++;
    }
    public static void modify(int a){
        a ++;
    }

    public static void modify(Student stu){
        stu.age ++;
    }
}


class Student{
    int age;
}
